1. Field of the Invention
The present invention relates to imaging systems. More specifically, the present invention relates to systems for providing multiple infrared images.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
In many applications, there is a need to provide multiple simultaneous real time images from a single sensor. In forward looking infrared (FLIR) systems, for example, many situations arise in which simultaneous wide angle and zoom views of a scene would be desirable. Previous known attempts to provide such capability have involved two or more sets of lenses and associated optical equipment, one for each field-of-view desired. Typified by boresighted optical fields-of-view, these systems often include an optical field-of-view which would be activated whenever the operator desired the alternate view. Unfortunately, there are several limitations associated with the simple provision of multiple optical arrangements to provide multiple fields-of-view of an object in real time.
Multiple optical arrangements can add significantly to the cost, size and weight of an imaging system. (This is particularly problematic with respect to FLIR systems which are generally expensive.) These systems are generally mechanically complex and have close manufacturing tolerances which require precision assembly and maintenance. Further, multiple optical arrangements generally increase the weight on the gimbal supporting the sensor and thereby limit the performance of the host system.
In addition, to the extent that systems equipped with such multiple optical arrangements provide multiple images of a scene, the zoomed image is generally confined to the center of the wide angle field-of-view. This common boresight limitation prevents a second operator from zooming in on a portion of the image outside of the boresight of the wide angle lens.
A particularly significant limitation of the multiple optical arrangement approach is that these systems do not provide simultaneous images per se. That is, as only one set of optics may be selected at a time, only one view is available at a time. This is an obvious limitation in situations in which it is desirable to provide a field-of-view for more than one operator at a time. With respect to military equipment, for example, it may be desirable to provide a driver with a wide angle field-of-view and a gunner with a simultaneous zoom view of a particular portion of a scene from the same image sensor.
An additional limitation of the multiple optical arrangement approach is that the magnification of the lenses is fixed and discretely limited. Only one magnification is available at a time.
Finally, there are many systems in the field for which this capability would be desirable. Yet the retrofit of existing systems to provide this limited conventional capability would be too expensive to provide a practical option.
Thus, there is a need in the art for an inexpensive nonmechanical system or technique for providing multiple simultaneous real time images providing diverse fields-of-view of a scene with diverse variable degrees of magnification and without mutual boresight interdependence. Ideally, the system would allow for a ready (noninvasive) retrofit into existing systems and would not degrade the performance thereof.